The present invention relates to electric appliances and, more specifically, to electric irons.
An electric iron consists essentially of a heating element and a means for controlling the application of electric power to the heating element. Thermostatic controls are conventionally employed to maintain a sole-plate temperature in a selectable range.
One of the long-felt problems of electric irons is a perceived danger of fire or injury resulting from an electric iron inadvertently being left energized for an extended period. One solution to this problem, disclosed in U.S. patent application Ser. Nos. 687,842 and 678,843, includes a timer and a motion sensor connected to cut off electric power to the heating element if the electric iron remains stationary for a predetermined period such as, for example, about 10 minutes.
Although the 10-minute cutoff cycle is appropriate for avoiding long-term operation of an electric iron in the absence of motion, if the soleplate of an electric iron remains stationary in contact with a fabric, or other material susceptible to heat damage, marking, charring, or other damage may occur long before the expiration of the 10-minute timing period. Reducing the timing period to a short enough value to avoid such damage interferes with normal usage of the electric iron which may be rested on its heel for several minutes while other tasks are undertaken by the operator.
The electronic and electro-mechanical components for operating an electric iron are conventionally contained in a hollow handle and a hollow forward pedestal. Modern styling of electric irons tends toward narrower and more angled designs, thereby reducing the amount of space available for the electronic and electro-mechanical components. Thus, more compact elements are desireable. Furthermore, it is desireable to reduce the manufacturing cost of such elements. One area of present interest for size and cost reduction is a relay switch used for breaking the power to the electric iron if the timer reaches the end of its cycle without being reset by the motion sensor.